Residents across the Rio Grande Valley may have noticed several empty or nearly empty canals.

During normal years, those canal would be full and carry thousands of gallons per second.

Cities across the Valley also get their water from these canals.

In a normal year, a city's share of the irrigation water would only be about 10% of the flow in a canal.

About 90% of that flow goes to agriculture.

Cities use about 280,000 acre feet per year.

In a good year, agriculture uses about a million acre feet.

The more water you have available, the better the flow.

A small amount of  water will stall and not reach its destination.

A large amount of water will flow properly.

The longer the distance, the more push water is needed.

Acre feet is a unit of measurement farmers use to describe the amount of water it takes to cover one acre in a foot of water.

An acre foot is enough to fill half an Olympic-sized swimming pool.

Valley cities use about 280,000 acre feet a year, or about half a million swimming pools.